What right of the colonists did the

Quartering Act violate?

was it the colonists right to privacy?

Check this article.

http://en.wikipedia.org/wiki/Quartering_Act

Yes. It was the colonists' right to privacy.

The Quartering Act of 1765 violated the colonists' right to property. It required the colonists to provide food, lodging, and other provisions to British soldiers who were stationed in their homes or in public buildings. This act was passed by the British Parliament as a means to reduce the cost of maintaining British troops in the American colonies, particularly after the French and Indian War. Not only did the Quartering Act infringe upon the colonists' property rights, but it also violated their privacy, as British soldiers were allowed to enter and stay in their homes without their consent.